Food on Ships | Secrets to Preserving Food

Food preservation is a battle against bacteria, a fight against fungi. On ship journeys, how have humans tried to win the microbial war?

“Englishmen, and more especially seamen, love their bellies above anything else,” wrote Samuel Pepys, famous 17th-century British diarist and administrator of the Navy.¹ Wherever we travel, we need to eat and drink, and this was a crucial problem for seafaring journeys. Pepys wrote during the Age of Sail (around 1571–1862). With long voyages of many weeks and months, how did they stop food from rotting?

Food Preservation Using Salt

Rotting occurs as fruit and vegetables ripen and begin to decay. On food, bacteria and fungi digest food, often producing toxins that make us sick, and odours which we have evolved to find distasteful. The microbial enemy is too numerous to wipe out—the more effective approach is to make it difficult or impossible for harmful microbes to grow.

Like other living things, bacteria need food, oxygen, water, warm temperatures, and a comfortable pH environment. Over a thousand years ago, the Vikings dried out fish and meat for their longboat journeys.³ But this was not the preferred method in the Age of Sail. Drying meat is a lengthy process, and it was hard to keep moisture out on long journeys. Instead, meat was preserved in barrels of salt and brine. Being in a salty environment draws water out of living cells ( through osmosis ), dehydrating the bacteria and keeping meat edible for months—though, taste being something of a secondary concern. Still, salted meat was far easier to keep on a ship than livestock animals.

Scurvy-Free with Sauerkraut?

Fruit and vegetables could also be pickled in sealed containers of acidic liquids like vinegar or sour whey (as the Vikings also used). Most bacteria can’t tolerate acidic environments. But some fermenting bacteria, like non-harmful and beneficial Lactobacillus can produce useful products and flavours. Though pickling and fermenting are two different processes, some pickled products are also fermented. As fermentation produces acid, fermented foods, from cheese to salami to sauerkraut also have a longer shelf-life.

Read more about fermentation and how it works.

But, in the past, the limited food on ships led to health problems. Scurvy, a degenerative disease caused by lack of vitamin C, was the ‘plague of the oceans’, and it was expected 50% of crews would die from the disease—at least two million people between 1500 and 1800.⁴ Taking sauerkraut on ship journeys would have helped to prevent scurvy since pickling preserves much of the vitamins in vegetables.  

But pickled vegetables didn’t have to be the only option—Chinese mariners had long avoided scurvy by taking soybeans on board, which provide vitamin C when they sprout.⁵

Preserving Food on Ships Today

Nowadays, the industrial age has brought canning, freezing and refrigerating to preserve even food on ships.

Although canned and preserved foods have entered a cruise’s menu, an abundance of fresh fruit and vegetables can be preserved through careful storage, refrigeration, and science. Fruit and vegetables produce ethylene gas as they ripen, which, in turn, speeds up the process. So ripening can be slowed by putting ethylene-absorbing mats in refrigerators, allowing salads to be available for over a month.

Read more about ripening and how it works.

But some age-old problems remain: microbes have to be slowed or controlled. While an abundance of fresh fruit and vegetables can be taken onboard, they need to be scrupulously checked for any mould or damage. There are also modern problems with food that is packaged, pasteurised and preserved.

I spoke to Bert Bakering, head chef of the marine research ship RV Falkor, to learn more about food and drink preservation aboard ships.⁶

“At some ports, you have fresh milk that only stays fresh for seven days, but in the United States, there is also milk that stays fresh for about 30 days,” Bert mused. “So, I need to find the right brands. And if you go to Fiji or those sorts of faraway places, a lot of stock is out of date when you buy it, or there are weevils inside the flour. So, we try to plan ahead. Because if you get 50 kilos of flour to make bread but have to throw it away, then I don’t have bread in the freezer…”

With onboard desalinisation plants, ships also have no shortage of fresh water–Falkor’s plants can produce around 1000L of freshwater an hour.

It seems nowadays, feeding a crew is no longer just a matter of survival and nutrition. The challenge is delivering taste and enjoyment in every meal for a crew typically requiring three meals a day, several hundred meals a week, and so a few thousand meals over several weeks…